Which algebraic expression represents this phrase?

To prepare 450 ml of a 30% (w/v) solution of potassium chloride (kcl), how many grams of solute are needed?

tiny-mole [99]

The important clue from the problem, would be (w/v). This would indicate that the percent has units of weight per volume. We calculate as follows:

Grams solute = .30 g solute / mL solution (450 mL) = 135 g of solute.

Hope this answers the question. Have a nice day.

4 0

4 years ago

∆abc is isosceles, ab = bc, and ch is an altitude. how long is ac, if ch = 84 cm and m∠hbc = m∠bac +m∠bch?

Tems11 [23]

Given that ∆abc is isosceles and ab = bc, then m<bac = m<acb and m<hbc = 180 - m<bac - m<acb

Given that m∠hbc = m∠bac +m∠bch, then m<hbc + m<bch = m<bac + 2m<bch

But m<hbc + m<bch = 90°, thus 90° = m<bac + 2m<bch

Also, m∠bac + m∠ach = 90° ⇒ m<bac + 2m<bch = m<bac + m<ach ⇒ 2m<bch = m<ach

Since, Δabc is isosceles with ab = bc ⇒ m<bac = m<acb.

Also, m<acb = m<ach + m<bch ⇒ m<acb = 3m<bch = m<bac

Since m<bch : m<ach = 1 : 2 ⇒ bh : ah = 1 : 2

Thus, $bh:bc:ch=1:3:\sqrt{8}$

Given that ch = 84 cm, then

$\frac{bc}{ch} = \frac{bc}{84} = \frac{3}{\sqrt{8}} \\ \\ \Rightarrow bc= \frac{3\times84}{\sqrt{8}} =63\sqrt{2}=ab$

Now, $ah= \frac{2}{3} (63\sqrt{2})=42\sqrt{2}$

$ac= \sqrt{ch^2+ah^2} \\ \\ = \sqrt{84^2+(42\sqrt{2})^2} \\ \\ = \sqrt{7056+3528} = \sqrt{10584} \\ \\ =42\sqrt{6}$

6 0

3 years ago

1/3k+80=1/2k+120 k=??

Sati [7]

Answer:

The value of k is 240

Step-by-step explanation:

$\frac{1}{3}k + 80 = \frac{1}{2}k + 120$